7-Alkylmercaptoacetamido cephalosporins

ABSTRACT

Cephalosporin compounds having various alkylmercaptoacetamido groups at position 7 and S-heterocyclic substituents at position 3 have been prepared and have antibacterial activity.

United States Patent DeMarinis et al.

[4 1 May 20, 1975 7-ALKYLMERCAPTOACETAMIDO CEPHALOSPORINS Inventors: Robert M. DeMarinis, King of Prussia; John R. E. Hoover, Glenside, both of Pa.

SmithKline Corporation, Philadelphia, Pa.

Filed: June 4, 1973 Appl. No.: 366,816

Assignee:

U.S. Cl. 260/243 C; 424/246 Int. Cl C07d 99/24 Field of Search 260/243 C References Cited UNITED STATES PATENTS l/l967 Flynn 260/243 C 3,445,463 5/1969 Van Heyningen l. 260/243 C 3,776,906 12/1973 Essery et al 260/243 C 3,776,907 12/1973 Essery et a] 260/243 C Primary Examiner-Nicholas S. Rizzo Attorney, Agent, or FirmJanice E. Williams; Alan D. Lourie; William H. Edgerton 7 Claims, No Drawings 7-ALKYLMERCAPTOACETAMIDO CEPHALOSPORINS This invention relates to cephalosporin compounds However, no 7-alkylmercaptoacetamido cephalospo rins incorporating a 3-S-heterocycle have been disclosed.

The compounds of this invention are prepared by acwhich have antibacterial activity. In particular, the in- 5 ylation of an aqueous solution of the sodium salt of the vention relates to compounds possessing an alkylmerappropriate 7-aminocephalosporanic acid nucleus, captoacetamido substituent at position 7 of the cephem where A CH Sl-let, with an appropriately substituted nucleus and an S-hetero substituent at position 3. alkylmercapto-acetic acid chloride.

The compounds of this invention are represented by The 7-amino e halo orin nuclei where A the following structure: 0 CH SHet are prepared by known methods from 7-aminocephalosporanic acid (7-ACA) and the appro- S priate heterocyclic mercaptan compound. RSCH ZCONH\ The cephalosporins of this invention possess antibacterial activity. They are active against both Gram- A positive and Gram-negative organisms. Minimum in- OOM hibitory concentrations (MIC) ranged from 0.2 to

200 ug./m1. in in vitro testing. Upon in vivo subcutaneous administration the compounds also show signifiin which: cant activity. These results are summarized in Tables 1 R is lower alkyl of one to six carbon atoms; and II; structures of the compounds appear in Table 111.

M is hydrogen or an alkali metal or ammonium cat- The compounds are formulated and administered by ion; and injection in the same manner as other cephalosporins A is Z Where Het is a five or six memb red with the dose depending on the subject and infection heterocyclic ring containing two to four atoms selected b i t t d,

TABLE I MlC (ug./m1.) in vitro Bacteria 26606 17316 00416 09626 S. aureus HH 127 0.804 0.2,0.4 0.4 1.6 S. uureus SK 23390 02,0.4 0.2 0.2 1.6 S. villaluz 12.5,25 1.6,25 0.8 50 Strep. faecalix 50, 25, 12.5 50

HH 34358 12.5 E. (011' SK 12140 1.6,0.8 1.6 3.1 3.1 E. (011' HH 33779 1.63.1 3.16.3 12.5 12.5 Kleb. pneumo. SK 4200 0.8 1.6 3.1 3.1 Kleb. pneumo. SK 1200 08,04 0.8.1.6 1.6 1.6 Pseudo. .i'p. HH 63 200 200 200 200 Salmonella ATCC 12176 0.8,04 04,0.8 1.6 1.6 Shigella HH 112 0.8.0.2. 0.4.0.8 1.6 1.6

Entero aerog. ATCC 13048 12 5,63 6.3.12.5 12.5 50 Serra. mart. ATCC 13880 200 200, 200 100 200 Enlem. cloacae Hl-l 31254 3.1 6.3

from the group consisting of N, O and S, unsubstituted -TABL or substituted with from one to two groups selected from lower alkyl, alkoxyalkyl 0r trifluoromethyl, each Com EDS (mg/kg) in vivo alkyl or alkoxy having from one to four carbon atoms. pound Preferred compounds are those where Het is unsub- E. (01! Kleb. pneumo. stltuted or methyl substituted trrazolyl, tetrazolyl, ox- 5O pa SC p0 azolyl, oxadiazolyl, thiazolyl or thradlazolyl. Also pre- 26606 2553,25 4146,41 21,145.11 71 ferred are compounds where R 18 methyl, ethyl or pro- 17316 6.2 29 25 200 pyl 00416 16 50 50 Included within the scope of this invention are the 200 pharmaceutically acceptable salts that are formed by reaction of the cephalosporanic acid with a pharmaceutically acceptable base.

Preparation of various 7- alky1mercaptoacetamidocephalosporanic acid deriva- TABLE tives is described, inter alia, in British Pat. No. 1,038,529 (1966) and U.S. Pat. Nos. 3,270,012 COMPOUND R A (1966) and 3,297,692 (1967). Brit sh Pat. 26606 met'hyl l methyl lyz,3y4 twa 1,038,529 discloses such compounds with a pyrldinizo1'5-y1-thiomethy1 ummethyl, imidazoliummethyl, or methylimidazolium- 17316 ethyl y U S Pat NO zo1-5-yl-thromethyl methyl substituent at the 3-pos1t1on, 00416 n.pmwi l ethyl-l,2,3,4-tetra- 3,297,692 discloses such compounds with a 3- v zo1-5-y1thiomethyl acetoxymethyl group. 0.5. Pat. No. 3,270,012 dis- 09626 methyl *mfihythltmawt closes generically 3-pyrridiniummethy1 compounds.

S-yIthiomethyl The following examples illustrate the invention but are not to be construed as limiting the scope thereof. Temperatures are in degrees Centigrade unless otherwise stated.

EXAMPLE 1 7-Amino-3-( l-methyll ,2,3,4-tetrazol--ylthiomethyl)- A -cephem-4-carboxylic acid To a suspension of 27.2 g. (0.1 mol.) of 7-ACA in 200 ml. of water and 100 ml. of acetone was added a solution of 18.9 g. of sodium bicarbonate in 200 ml. of water. The resultant solution was warmed on a steam bath and a solution of 14.5 g. (0.125 mol.) of l-methyl- 5-mercapto-1,2,3,4-tetrazole in 200 ml. of acetone was added. The reaction mixture was refluxed for 3.5 hr. while maintaining the pH at 7.48.0 by addition of 5 percent sodium bicarbonate. Acidification of the cooled reaction mixture to pH 3.5 with 6N hydrochloric acid resulted in precipitation of 7-amino-3-(1- methyl-1,2,3,4-tetrazol-5-ylthiomethyl)-A -cephem-4- carboxylic acid which was collected, washed with water and air-dried (16 g.; 49 percent).

EXAMPLE 2 7-Methylmercaptoacetamido-3-( l-methyl-l ,2,3,4- tetrazol-S-ylthiomethyl)-A -cephem-4-carboxylic acid To a stirred, cooled (20) solution of 8.50 g. (0.026 mol.) of 7-amino-3-( l-methyll ,2,3,4-tetrazol-5- ylthiomethyl)-A -cephem-4-carboxylic acid in 220 ml. of 3 percent sodium bicarbonate and 220 ml. of acetone was dropwise added a solution of 3.66 g. (0.029 mol.) of methylmercaptoacetyl chloride in 52 ml. of acetone, during which time the pH of the reaction mixture was maintained at 8.0 by addition of 10 percent sodium hydroxide. After addition the reaction mixture was stirred an additional 20 minutes at then was warmed to room temperature and extracted with ether. The remaining aqueous phase was cooled, 250 ml. of ethyl acetate was added and the slurry was acidified to pH 3.5 with 3N hydrochloric acid. The layers were separated and the aqueous phase was extracted twice more with ethyl acetate. The combined extracts were dried (MgSO and concentrated in vacuo to yield 6.8 g. of a gummy solid that was chromatographed on 300 g. of silica gel with CHCl :iPrOH:HCO H (90: 10:3) to yield 4.6 g. (43 percent) of 7-methylmercaptoacetamido-3- 1-methyl-1,2,3 ,4-tetrazol-5-ylthiomethyl)-A -cephem- 4-carboxylic acid. Conversion to the corresponding sodium salt was accomplished by addition of 2.6 ml. of a 30 percent solution of sodium 2-ethy1hexanoate in isopropanol to a solution of 2.0 g. of the free acid in ml. of methanol. Ether (100 ml.) was added to precipitate the salt which was collected, washed with ether and dried in vacuo.

C, H, N O,S .Na.1H O (456.516) Theory Found C 34.19 34.19 H 3.41 3.49 N 18.40 18.74

EXAMPLE 3 7-Ethylmercaptoacetamido-3-( l-methyl-1,2,3,4- tetrazol-S-ylthiomethyl)-A -cephem-4-carboxylic acid The procedure as described in Example 2 was followed utilizing 2.95 g. (0.009 mol.) of 7-amino-3-(1- methyl- 1 ,2,3,4-tetrazol-5-ylthiomethy1)-A -cephem-4- carboxylic acid in 60 ml. of 3 percent sodium bicarbonate and 60 ml. of acetone and 1.38 g. (0.010 mol.) of ethylmercaptoacetyl chloride in 20 ml. of acetone. The acidified (pH 2.8) aqueous solution was extracted with ethyl acetate and the combined extracts were washed (H O), dried (MgSO and concentrated in vacuo to yield 2.38 g. (62 percent) of 7- ethylmercaptoacetamido-3-( l-methyl-l ,2,3,4-tetrazol- 5-ylthiomethyl)-A -cephem-4-carboxy1ic acid. The free acid (2.3 g.) was dissolved in 50 ml. of ethyl acetate and 3.06 ml. of a 30 percent solution of sodium 2- ethylhexanoate in isopropanol was added. The solution was filtered and 200 ml. of ether was added to the filtrate to precipitate the salt which was collected, washed with ether and dried in vacuo. Recrystallization from methanol afforded 1.39 g. of the pure salt.

H I7 S 4 J-Na (452.527)

7-n-Propylmercaptoacetamido-3-( l-methyll ,2,3 ,4- tetrazol-5-ylthiomethyl)-A -cephem-4-carboxylic acid To a stirred, cooled (10C.) solution of 3.28 g. (0.010 mol.) of 7-amino-3-(l-methyl-l,2,3,4-tetrazol- 5-ylthiomethyl)-A -cephem-4-carboxylic acid in 62.5 ml. of 3 percent sodium bicarbonate and 62.5 ml. of acetone was added dropwise a solution of 1.84 g. (0.012 mol.) of n-propylmercaptoacetyl chloride in 20 ml. of acetone, during which time the pH of the reaction mixture was maintained at 7.6-8.0 with 10 percent sodium hydroxide. After addition the reaction mixture was stirred an additional 20 minutes in the cold, then it was warmed to room temperature, diluted with ml. of water, and extracted with ether. Ethyl acetate ml.) was added to the aqueous phase which was then acidified to pH 2.5 with 3N hydrochloric acid. The layers were separated and the aqueous phase was again extracted with ethyl acetate. The combined extracts were washed (H O), dried (MgSO and concentrated in vacuo to give 3.0 g. (67 percent) ofa yellow foam identified as 7-n-propylmercaptoacetamido-3-(l-methyl- 1,2,3,4-tetrazol-5-y1thiomethyl)-A -cephem-4- carboxylic acid. The crude acid (3.0 g.) was dissolved in 25 ml. of ethyl acetate and 25 ml. of acetone to which was added a 30 percent solution of sodium 2- ethylhexanoate to pH 6.3. The precipitated sodium salt was collected, washed with ether and dried in vacuo. Addition of ether to the filtrate caused additional amounts of salt to precipitate which were combined with the first crop and recrystallized from methanolether to give 1.27 g. of pure salt.

7-Amino-3-( 4-methyll ,2,4-triazol-3-ylthiomethyl)-A cephem-4-carboxylic acid The title compound was obtained from reaction of 7-ACA and 4-methyl-3-mercapto-l,2,4-triazole by the same procedure as described in Example 1.

EXAMPLE 6 7-Methylmercaptoacetamido-3-(4-methyl-l ,2,4- triazol-3-ylthiomethyl)-A -ccphem-4-carboxylic acid The procedure as described in Example 2 was followed utilizing 3.92 g. (0.013 mol.) of 7-amino-3-(4- methyl-l ,2,4-triazol-3-ylthiomethyl)-A -cephem-4- carboxylic acid in 80 ml. of 3 percent sodium bicarbonate and 80 ml. of acetone and 1.7 g. (0.013 mol.) of methylmercaptoacetyl chloride in 25 ml. of acetone. The acidified (pH 3.5) aqueous solution was extracted with ethyl acetate then concentrated in vacuo to yield, upon cooling, 7-methylmercaptoacetamido-3-(4- methyl-l ,2,4-triazol-3-ylthiomethyl)-A -cephem-4- carboxylic acid. The acid was dissolved in methanol, the solution was filtered, and a percent solution of sodium methoxide in methanol was added to pH 6.8. Addition of ether to this solution caused precipitation of the sodium salt which was collected and recrystallized from methanol-ether to give 0.62g. of pure material.

14 1s O4S .Na.2H O

Theory Found C 35.51 35.98 H 4.25 336 N 14.78 14.17

EXAMPLE 7 7-amino-3-( 3-ethyll ,2,4-thiadiazol-5-ylthiomethyl A -cephem-4-carboxylic acid 7-amino-3-thiazol-5-ylthiomethyl)-A -cephem-4- carboxylic acid 7-amino-3-(2-methylthiazol-5-ylthiomethyl)-A cephem-4-carboxylic acid 7-amino-3-(4-methylthiazol-5-ylthiomethyl )-A cephem-4-carboxylic acid 7-amino-3-( 2,4-dimethylthiazol-S-ylthiomethyl )-A cephem-4-carboxylic acid 7-amino-3-( 2-ethylthiazol-5-ylthiomethyl )-A cephem-4-carboxylic acid 7-amino-3-(4-ethylthiazol-5-ylthiomethyl)-A cephem-4-carboxylic acid 7-amino-3-(2,4-diethylthiazol-5-ylthiomethyl)-A cephem-4-carboxylic acid 7-amino-3-( l,3,4-oxadiazol-2-ylthiomethyl)-A cephem-4-carboxylic acid 7-amino-3-( S-methyll ,3 ,4-oxadiazol-2- ylthiomethyl)-A -cephem-4-carboxylic acid 7-amino-3-(oxazol-S-ylthiomethyl)-A -cephem-4- carboxylic acid 7-amino-3-(2-methyloxazol-5-ylthiomethyl)-A cephem-4-carboxylic acid 7-amino-3-(4-methyloxazol-5-ylthiomethyl)-A cephem-4-carboxylic acid 7-amino-3-(2,4-dimethyloxazol-5-ylthiomethyl)-A cephem-4-carboxylic acid 7-amino-3-(2-ethyloxazol-5-ylthiomethyl)-A cephem-4-carboxylic acid 7-amino-3-(4-ethyloxazol-5-ylthiomethyl)-A cephem-4-carboxylic acid 7-amino-3-( 2,4-diethyl0xaz0l-5-ylthiomethyl-A cephem-4-carboxylic acid 7-amino-3-( l ,2,3,4-tetrazol-5-ylthiomethyl )-A cephem-4-carboxylic acid 7-amino-3-( l-ethyl-l ,2,3,4-tetrazol-5-ylthiomethyl)- A -cephem-4-carboxylic acid 7-amino-3-( l-methoxymethyll ,2,3 ,4-tetrazol-5- ylthiomethyl)-A -cephem-4-carboxylic acid 7-amino-3-( l,2,4-triazol-3-ylthiomethyl)-A cephem-4-carboxylic acid 7-amino-3-( S-methyll ,2,4-triaz0l-3-ylthiomethyl)- A -cephem-4-carboxylic acid 7-amino-3-( l-methyll ,2,4-triaZol-5-ylthiomethyl)- A -cephem-4-carboxylic acid 7-amino-3-( l ,S-dimethyll ,2,4-triazol-3-ylthiomethyl)-A -cephem-4-carboxylic acid 7-amino-3-(4,5-diemthyl-1,2,4-triazol-3-ylthiomethyl)-A -cephem-4-carboxylic acid 7-amino-3-( 4-ethyl- 1 ,2,4-triaZol-3-ylthiomethyl )-A cephem-4-carboxylic acid 7-amino-3-( S-ethyl-l ,2,4-triazol-3-ylthiomethyl)-A cephem-4-carboxylic acid 7-amino-3-( l-ethyl-l ,2,4-triazol-5-ylthiomethyl )-A cephem-4-carboxylic acid 7-amino-3-(4,5-diethyl-l ,2,4-triazol-3- ylthiomethyl)-A -cephem-4 carboxylic acid 7-amino-3-( 1,3-diethyl-l ,2,4-triazol-5- ylthiomethyl)-A -cephem-4-carboxylic acid 7-amino-3-( l ,3-diethyll ,2,4-triazol-3-ylthiomethyl)-A -cephem-4-carboxylic acid 7-amino-3-( 4-methyl-5-trifluoromethyll ,2,4-rriazol- 3-ylthiomethyl)-A -cephem-4-carboxylic acid 7-amino-3-(4-allyll ,2,4-triazol-3-ylthiomethyl )-A cephem-4-carboxylic acid 7-amino-3-( l ,2,3-triazol-4-ylthiomethyl)-A cephem-4-carboxylic acid 7-amino-3-( 3-methyll ,2,3-triazol-4-ylthiomethyl)- A -cephem-4-carboxylic acid 7-amino-3-( S-methyll ,2,3-triazol--ylthiomethyl A -cephem-4-carboxylic acid 7-amino-3-( 3,5-dimethyl-l ,2,3-triazol-4- ylthiomethyl)-A -cephem-4-carboxylic acid 7-amino-3-( 3-ethyl-l ,2,3-triazol-4-ylthiomethyl )-A cephem-4-carboxylic acid 7-amino-3-( S-ethyll ,2 ,3-triazol-4-ylthiomethyl )-A- cephem-4-carboxylic acid 7-amino-3-(3,5-diethyl-1,2,3-triazol-4- ylthiomethyl)-A -cephem-4-carboxylic acid 7-amino-3-( 3-methoxymethyl-l ,2,3-triazol-4- ylthiomethyl)-A -cephem-4-carboxylic acid 7-amino-3-(4-pyridylthiornethyl)-A -cephem-4- carboxylic acid 7-amino-3-(3-pyridylthiomethyl)-A -cephem-4- carboxylic acid 7-amino-3-(4-pyrimidylthiomethyl)-A -cephem-4- carboxylic acid 7-amino-3-(Z-pyrazinylthiomethyl)-A -cephem-4- carboxylic acid.

EXAMPLE 8 When the procedure of Example 2 is followed using a 7-amin0-3-heterocyclicthiomethylcephalosporin listed in Example 7, the corresponding 7- methylmercaptoacetamido-3-heterocyclicthiomethyl- A -cephem-4-carboxylic acid is obtained.

EXAMPLE 9 When the procedure of Example 3 is followed using a 7-amino-3-heterocyclicthiomethylcephalosporin listed in Example 7, the corresponding 7-ethylmercaptoacetamido-3- heterocyclicthiomethyl-A -cephem-4-carboxylic acid is obtained.

EXAMPLE 10 When the procedure of Example 4 is followed using a 7-amino-3-heterocyclicthiomethylcephalosporin listed in Example 7, the corresponding 7-npropylmercaptoacetamido-3-heterocyclicthiomethyl- A -cephem-4-carboxylic acid is obtained.

EXAMPLE 1 1 An injectable pharmaceutical composition is formed by adding sterile water or sterile saline solution (2 ml.)

a similar manner.

What is claimed is: l. A compound of the formula:

RSCH CON'HT in which:

R is lower alkyl of one to six carbon atoms;

M is hydrogen or an alkali metal or ammonium cation; and

A is CH SI-Iet, where Het is a five or six membered heterocyclic ring containing two to four atoms selected from the group consisting of N, O and S, unsubstituted or substituted with from one to two groups selected from lower alkyl, alkoxyalkyl or trifluoromethyl, each alkyl or alkoxy having from one to four carbon atoms.

2. A compound as claimed in claim 1 where R is methyl, ethyl or propyl.

3. A compound as claimed in claim 2 where Het is triazolyl, tetrazolyl, oxazolyl, oxadiazolyl, thiazolyl or thiadiazolyl unsubstituted or substituted with one or two alkyl groups of one to four carbon atoms.

4. A compound as claimed in claim 3 being the compound 7-methylmercaptoacetamido-3-( l-methyll ,2,3,4-tetrazol-5-ylthiomethyl)-A -cephem-4- carboxylic acid.

5. A compound as claimed in claim 3 being the compound 7-ethylmercaptoacetamido-3-( l-rnethyll ,2,3,4-tetrazol-5-ylthiomethyl)-A -cephem-4- carboxylic acid.

6. A compound as claimed in claim 3 being the compound 7-n-propylmercaptoacetamido-3-( l-methyll ,2,3 ,4-tetrazol-5-ylthiomethyl)-A -cephem-4- carboxylic acid.

7. A compound as claimed in claim 3 being the compound 7-methylmercaptoacetamido-3-(4-methyll ,2,4-triazol-5-ylthiomethyl)-A -cephem-4-carboxylic acid. 

1. A COMPOUND OF THE FORMULA:
 2. A compound as claimed in claim 1 where R is methyl, ethyl or propyl.
 3. A compound as claimed in claim 2 where Het is triazolyl, tetrazolyl, oxazolyl, oxadiazolyl, thiazolyl or thiadiazolyl unsubstituted or substituted with one or two alkyl groups of one to four carbon atoms.
 4. A compound as claimed in claim 3 being the compound 7-methylmercaptoacetamido-3-(1-methyl-1,2,3,4-tetrazol-5-ylthiomethyl)- Delta 3-cephem-4-carboxylic acid.
 5. A compound as claimed in claim 3 being the compound 7-ethylmercaptoacetamido-3-(1-methyl-1,2,3,4-tetrazol-5-ylthiomethyl)- Delta 3-cephem-4-carboxylic acid.
 6. A compound as claimed in claim 3 being the compound 7-n-propylmercaptoacetamido-3-(1-methyl-1,2,3,4-tetrazol-5-ylthiomethyl)- Delta 3-cephem-4-carboxylic acid.
 7. A compound as claimed in clAim 3 being the compound 7-methylmercaptoacetamido-3-(4-methyl-1,2,4-triazol-5-ylthiomethyl)- Delta 3-cephem-4-carboxylic acid. 